Commit 9557c3cf authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "7 fixes"

* emailed patches from Andrew Morton <>:
  mm/fadvise.c: do not discard partial pages with POSIX_FADV_DONTNEED
  mm: introduce dedicated WQ_MEM_RECLAIM workqueue to do lru_add_drain_all
  kernel/relay.c: fix potential memory leak
  mm: thp: broken page count after commit aa88b68c
  revert "mm: memcontrol: fix possible css ref leak on oom"
  kasan: change memory hot-add error messages to info messages
  mm/hugetlb: fix huge page reserve accounting for private mappings
parents 147d9e7b 18aba41c
......@@ -614,6 +614,7 @@ struct rchan *relay_open(const char *base_filename,
kref_put(&chan->kref, relay_destroy_channel);
return NULL;
......@@ -126,6 +126,17 @@ SYSCALL_DEFINE4(fadvise64_64, int, fd, loff_t, offset, loff_t, len, int, advice)
start_index = (offset+(PAGE_SIZE-1)) >> PAGE_SHIFT;
end_index = (endbyte >> PAGE_SHIFT);
if ((endbyte & ~PAGE_MASK) != ~PAGE_MASK) {
/* First page is tricky as 0 - 1 = -1, but pgoff_t
* is unsigned, so the end_index >= start_index
* check below would be true and we'll discard the whole
* file cache which is not what was asked.
if (end_index == 0)
if (end_index >= start_index) {
unsigned long count = invalidate_mapping_pages(mapping,
......@@ -832,8 +832,27 @@ static bool vma_has_reserves(struct vm_area_struct *vma, long chg)
* Only the process that called mmap() has reserves for
* private mappings.
if (is_vma_resv_set(vma, HPAGE_RESV_OWNER))
return true;
if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
* Like the shared case above, a hole punch or truncate
* could have been performed on the private mapping.
* Examine the value of chg to determine if reserves
* actually exist or were previously consumed.
* Very Subtle - The value of chg comes from a previous
* call to vma_needs_reserves(). The reserve map for
* private mappings has different (opposite) semantics
* than that of shared mappings. vma_needs_reserves()
* has already taken this difference in semantics into
* account. Therefore, the meaning of chg is the same
* as in the shared case above. Code could easily be
* combined, but keeping it separate draws attention to
* subtle differences.
if (chg)
return false;
return true;
return false;
......@@ -1816,6 +1835,25 @@ static long __vma_reservation_common(struct hstate *h,
if (vma->vm_flags & VM_MAYSHARE)
return ret;
else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && ret >= 0) {
* In most cases, reserves always exist for private mappings.
* However, a file associated with mapping could have been
* hole punched or truncated after reserves were consumed.
* As subsequent fault on such a range will not use reserves.
* Subtle - The reserve map for private mappings has the
* opposite meaning than that of shared mappings. If NO
* entry is in the reserve map, it means a reservation exists.
* If an entry exists in the reserve map, it means the
* reservation has already been consumed. As a result, the
* return value of this routine is the opposite of the
* value returned from reserve map manipulation routines above.
if (ret)
return 0;
return 1;
return ret < 0 ? ret : 0;
......@@ -763,8 +763,8 @@ static int kasan_mem_notifier(struct notifier_block *nb,
static int __init kasan_memhotplug_init(void)
pr_err("WARNING: KASAN doesn't support memory hot-add\n");
pr_err("Memory hot-add will be disabled\n");
pr_info("WARNING: KASAN doesn't support memory hot-add\n");
pr_info("Memory hot-add will be disabled\n");
hotplug_memory_notifier(kasan_mem_notifier, 0);
......@@ -1608,7 +1608,7 @@ static void memcg_oom_recover(struct mem_cgroup *memcg)
static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order)
if (!current->memcg_may_oom || current->memcg_in_oom)
if (!current->memcg_may_oom)
* We are in the middle of the charge context here, so we
......@@ -667,6 +667,24 @@ static void lru_add_drain_per_cpu(struct work_struct *dummy)
static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work);
* lru_add_drain_wq is used to do lru_add_drain_all() from a WQ_MEM_RECLAIM
* workqueue, aiding in getting memory freed.
static struct workqueue_struct *lru_add_drain_wq;
static int __init lru_init(void)
lru_add_drain_wq = alloc_workqueue("lru-add-drain", WQ_MEM_RECLAIM, 0);
if (WARN(!lru_add_drain_wq,
"Failed to create workqueue lru_add_drain_wq"))
return -ENOMEM;
return 0;
void lru_add_drain_all(void)
static DEFINE_MUTEX(lock);
......@@ -686,7 +704,7 @@ void lru_add_drain_all(void)
pagevec_count(&per_cpu(lru_deactivate_pvecs, cpu)) ||
need_activate_page_drain(cpu)) {
INIT_WORK(work, lru_add_drain_per_cpu);
schedule_work_on(cpu, work);
queue_work_on(cpu, lru_add_drain_wq, work);
cpumask_set_cpu(cpu, &has_work);
......@@ -252,7 +252,10 @@ static inline void free_swap_cache(struct page *page)
void free_page_and_swap_cache(struct page *page)
if (is_huge_zero_page(page))
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